Air filtration system



FIG. 1 illustrates a view of the air filtration system showing first and second sides.

FIG. 2 illustrates a view of the air filtration system showing the second and third sides.

FIG. 3 illustrates a view of the air filtration system showing the first and fourth sides; and,

FIG. 4 illustrates the underside of the air filtration system, shown enlarged.

The broken line showing is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for an air filtration system, as shown and described. 